1. Field of the Invention
The present invention relates to a connecting system, including a pilot clutch brought into an engaged state by an actuator, a cam means operated by an engaging force of the pilot clutch, an urging member driven and moved by the cam means, and a main clutch brought into an engaged state by a movement of the urging member, the cam means including a first cam ring restrained by the pilot clutch, a second cam ring provided on the urging member, and a rolling member interposed between the first and second cam rings for converting the relative rotation of the cam rings into a thrust.
2. Description of the Prior Art
There are such conventionally known connecting systems described in Japanese Patent Application Laid-open Nos. 219123/91 and 107347/92. These conventional connecting systems were applied to a differential motion limiting mechanism in a differential in an automobile so as to control the differential motion limiting mechanism, by utilizing an engaging force of the pilot clutch and bringing the main clutch into its engaged state.
In the above prior art connecting systems, a drag torque may be generated, in some cases, in the pilot clutch, due to the viscosity of oil, particularly at a low temperature, or the like. This drag torque may be applied to the first cam ring to bring about a relative rotation between both the first and second cam rings, thereby bringing the main clutch into its engaged state to generate a differential motion limiting force larger than necessary.